1. Field of the Invention
The present invention relates to a technology of inspecting a photo device.
2. Description of the Background Art
Conventionally, there has been a technology of irradiating a photo device such as a solar cell with light to inspect the photo device based on an electromagnetic wave that is emitted from the photo device in response to the irradiation (for example, see Japanese Patent Application Laid-Open No. 2013-19861).
However, in the case of photo devices, such as a multi-junction type solar cell, which have a portion in which an absorption wavelength region varies in a depth direction, the light reaches a specific depth only by irradiating the photo device with light having a specific wavelength, and only the electromagnetic wave generated at the specific depth can be detected. Therefore, there is a room for improvement in the conventional inspection technology.